<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>this</title>
</head>
<script>
    var obj = {a:1,b:function(){
        console.log(this)
    }}
    var fun = obj.b
    fun()
</script>
<body>
    
</body>
</html>